Recovery of modifier compounds and polar organic compounds from a poly(arylene sulfide) recycle mixture

Abstract

A process is provided to recover at least one modifier compound and at least one polar organic compound from a P(AS) recycle mixture.

That which is claimed is:  
     
       1. A process to recover at least one polar organic compound and at least one modifier from a P(AS) recycle mixture comprising said at least one polar organic compound, said at least one modifier and methanol, said process comprising passing said P(AS) recycle mixture along with water to a separation zone; and 
       recovering polar organic compound and modifier as a recycle feedstock mixture.  
     
     
       2. A process according to claim  1  wherein said P(AS) recycle mixture is produced by a process comprising: 
       1) contacting a quench process reaction mixture with methanol to produce a quench process methanol-rich mixture;  
       wherein said quench process reaction mixture comprising high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one polar organic compound, at least one modifier compound, and an alkali metal halide by-product;  
       2) separating said quench process methanol-rich mixture to produce a high molecular weight poly(arylene sulfide) product, said P(AS) recycle mixture, and optionally, a low molecular weight poly(arylene sulfide) stream;  
       wherein said P(AS) recycle mixture comprises methanol, said polar organic compound, and said modifier compound; wherein said low molecular weight poly(arylene sulfide) stream comprises low molecular weight poly(arylene sulfide) and cyclic and linear poly(arylene sulfide) oligomers.  
     
     
       3. A process according to claim  1  wherein said P(AS) recycle mixture is produced by a process comprising: 
       1) contacting a quench process reaction mixture comprising high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one POC, at least one modifier, and an alkali metal halide by-product with at least one polar organic compound at a temperature sufficient to dissolve substantially all of said low molecular weight poly(arylene sulfide) and cyclic and linear oligomers to produce a quench process polar organic compound-rich mixture;  
       2) separating said quench process polar organic compound-rich mixture to produce a quench process solid stream and a quench process liquid stream;  
       wherein said quench process solid stream is in a substantially solid form and comprises said high molecular weight poly(arylene sulfide), said polar organic compound, said modifier compound, and said alkali metal halide by-product;  
       wherein said quench process liquid stream is in a substantially liquid form and comprises substantially all of said low molecular weight poly(arylene sulfide) and cyclic and linear poly(arylene sulfide) oligomers, said polar organic compound, and said modifier compound;  
       3) contacting said quench process solid stream with methanol to produce a quench process methanol-rich poly(arylene sulfide) product mixture; and  
       4) separating said quench process methanol-rich poly(arylene sulfide) product mixture to produce a high molecular weight poly(arylene sulfide) product and said P(AS) recycle mixture;  
       wherein said recycle mixture comprises methanol, said polar organic compound, and said modifier compound.  
     
     
       4. A process according to claim  3  wherein said P(AS) recycle mixture is produced by a process comprising: 
       1) contacting said quench process liquid stream with methanol to produce a quench process methanol-rich low molecular weight poly(arylene sulfide) mixture;  
       2) separating said quench process methanol-rich low molecular weight poly(arylene sulfide) mixture to produce a low molecular weight poly(arylene sulfide) product and a second P(AS) recycle mixture;  
       wherein said second P(AS) recycle mixture comprises methanol, said polar organic compound, and said modifier compound; and  
       wherein said low molecular weight poly(arylene sulfide) product comprises said low molecular weight poly(arylene sulfide) and cyclic and linear poly(arylene sulfide) oligomers.  
     
     
       5. A process according to claim  1  wherein said P(AS) recycle mixture is produced by a process comprising: 
       1) contacting a flash process reaction mixture with methanol to produce a flash process methanol-rich mixture;  
       wherein said flash process reaction mixture comprises high molecular weight poly(arylene sulfide) product, low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one POC, at least one modifier, and an alkali metal halide by-product  
       2) separating said flash process methanol-rich mixture to produce a poly(arylene sulfide) product and said P(AS) recycle mixture;  
       wherein said poly(arylene sulfide) product comprises high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), and cyclic and linear poly(arylene sulfide) oligomers;  
       wherein said P(AS) recycle mixture comprises methanol, said polar organic compound, and said modifier compound.  
     
     
       6. A process according to claim  1  wherein said P(AS) recycle mixture is produced by a process comprising: 
       1) contacting a flash process reaction mixture comprising high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one POC, at least one modifier, and an alkali metal halide by-product with at least one polar organic compound at a temperature sufficient to dissolve a majority of said low molecular weight poly(arylene sulfide) and cyclic and linear oligomers to produce a flash process polar organic compound-rich mixture;  
       2) separating said flash process polar organic compound-rich mixture to produce a flash process solid stream and a flash process liquid stream;  
       wherein said flash process solid stream is in a substantially solid form and comprises insoluble poly(arylene sulfide), said polar organic compound, said modifier compound, and said alkali metal halide by-product;  
       wherein said flash process liquid stream is in a substantially liquid form and comprises soluble poly(arylene sulfide) and said polar organic compound;  
       3) contacting said flash process solid stream with methanol to produce a flash process methanol-rich poly(arylene sulfide) product mixture; and  
       4) separating said flash process methanol-rich poly(arylene sulfide) product mixture to produce a high molecular weight poly(arylene sulfide) product and said P(AS) recycle mixture;  
       wherein said P(AS) recycle mixture comprises methanol, said polar organic compound, and modifier compound.  
     
     
       7. A process according to claim  6  firther comprising recycling said flash process liquid stream to a poly(arylene sulfide) polymerization process. 
     
     
       8. A process according to claim  1  wherein said recycle feedstock mixture is recovered as a liquid. 
     
     
       9. A method according to claim  1  wherein said water is added in an amount sufficient to form a solution of said at least one modifier compound in said separation zone. 
     
     
       10. A method according to claim  1  wherein said water is added in an amount within the range of 2-10 moles of said water per mo le of said modifier compound. 
     
     
       11. A method according to claim  1  wherein said water is added in an amount within the range of 3-8 moles of said water per mole of said modifier compound. 
     
     
       12. A method according to claim  4  wherein said water is added in an amount within the range of 2-10 moles of said water per mole of said modifier compound. 
     
     
       13. A method according to claim  5  wherein said water is added in an amount within the range of 2-10 moles of said water per mole of said modifier compound. 
     
     
       14. A method according to claim  7  wherein said water is added in an amount within the range of 2-10 moles of said water per mole of said modifier compound. 
     
     
       15. A process according to claim  14  wherein said P(AS) is poly(phenylene sulfide) and said polar organic compound is NMP. 
     
     
       16. A process according to claim  1  wherein said P(AS) is poly(phenylene sulfide) and said polar organic compound is NMP.